Energy storage is accomplished by devices and/or physical media configured to receive and to store energy, and to provide the stored energy that is to be consumed or used at a later time (on demand) for useful operations as may be required. A device configured to store energy is called an energy-accumulation apparatus.
A renewable-energy system (such as a wind turbine and/or a solar panel) is configured to convert energy received from a renewable-energy source (wind and/or solar) into electricity, which may be classified as intermittent electric power. Wherever intermittent power sources are connected to (deployed in) an electrical grid (or grid), energy storage becomes an option to improve reliable supply of energy.
The excess electricity generated by the renewable-energy system can be used to manufacture pressurized air, which is then stored in an underwater compressed air system. Underwater compressed air systems generally store excess energy as compressed air underwater. This stored compressed air is then converted back into electricity when needed, upon demand, by using conversion systems for such a process (for example, when there is an energy production deficiency); then, the converted electricity is placed on an electric grid for subsequent distribution to electric users. Using these energy storage and retrieval systems can help electric utilities provide a supply of electricity when the demand is relatively higher without the need to constantly produce excess energy.